The percent PRA value is a measure of a patient’s level of sensitization to HLA antigens. It is the percentage of cells from a panel of blood donors against which a potential recipient’s serum reacts. The PRA reflects the percentage of the general population that a potential recipient makes antibodies (is sensitized) against. For example, a patient with a PRA of 80 percent will be incompatible with 80 percent of potential donors. Kidney patients with a high PRA are given priority on the waiting list. The higher the PRA, the more sensitized a patient is to the general donor pool, and thus the more difficult it is to find a suitable donor. A patient may become sensitized as a result of pregnancy, a blood transfusion, or a previous transplant. (OPTN Glossary May 2021)
Glossary Term